Statoil has recently done a large and complex architecture remake of a business critical application. The overall plan was to go from a situation with a codebase that was really hard, time consuming and riskful to make even small changes to and transform that into a situation with a codebase starting to get in control, and thereby making it smooth to make business driven improvements. In this presentation we’d like to share with you the story including what we learned and the key takeaways, both the happy parts and the tougher parts, both the technical aspects and the people things and more.